The present invention relates to a device to enable a high speed drill to be safely used around the spinal cord and nerve roots in the removal of bone material during the course of spinal surgery. It is particularly concerned with such a device which provides an advancing mechanism to precisely direct the drill in all planes of movement and a foot plate which is positioned beneath the bone material to be removed to shield the spinal cord and nerve roots and provide a counterforce to the cutting force applied through the drill.
The most common cutting tool used to remove bone material in spinal surgery is a cutting rongeur. Such devices employ a manual snipping action and are not power driven. They are somewhat similar to principle to the present invention, however, in that they employ a hooked end which is engaged beneath the material to be cut and a cutter which moves a guided path toward the hooked end.
The prior art also teaches surgical bone punches which function much like a conventional paper punch, and various types of cutters which employ saw or router-like elements which are shielded by foot or leg-like structures. In the latter devices, however, the foot or leg-like structures are stationary in relation to the cutting mechanism. They do not provide for movement of the cutting mechanism toward a foot plate which is engaged beneath the bone material being worked upon, and do not provide the precise control which is effected through means of the counterforce provided by the foot plate of the present invention.